KR830000613B1 - Method of manufacturing polyurethane coating - Google Patents

Abstract

No content.

Description

Method of manufacturing polyurethane coating

1 is a cross-sectional view of the instrument panel.

2 is a cross-sectional view showing a state during molding of the instrument panel pad.

The present invention relates to a method for producing a polyurethane coating body by pressing a metal material to form a core material and coating a required portion of the core material with polyurethane.

After pressing this kind of metal material to form the core material, the polyurethane coating on the desired place of the core material is applied to the instrument panel pads, sheets, overhead console box, door trim and seat of the car. In addition to interior materials such as arm rests and knee pads, the present invention is applied to the manufacture of bumpers and the like.

Conventionally, a metal material is pressed to form a core material, and a surface thereof is coated with pulley urethane, for example, to manufacture the instrument panel pad, to prevent rust during transportation and storage. Iii) The coated metal material (usually steel or galvanized steel) is dried to the dimensions and punched (blanked), followed by press lubricating oil (mainly mineral oil-based high-viscosity lubricants, eg Nippon Kosa Co., Ltd. G 634). And the like), and then press working to obtain the desired shape. All.

The molded metal material obtained in this step is a core material (commonly referred to as an insertion member), which is coated with a steel sheet in advance in order to coat the surface of the required part with polyurethane, or to obtain sufficient adhesive force between the pulley and the core material. It is important to completely remove the rust inhibitor and the press lubricating oil applied at the time of press working, and thus a degreasing step was required.

The procedure of the manufacturing process of the instrument pad is shown in the first table.

This conventional process sequence involves the following drawbacks.

1. The process order is good. (The number of processes is high and the consumption of effort is large.)

2. In order to form a sufficient adhesion state between the press-formed core material and the pulley urethane in the process after using the press lubricating oil mainly composed of mineral oil system, the rust preventive material and the press lubricating oil are completely removed and cleaned as described above. Degreasing process is needed.

3. Press lubricants based on mineral oil have a high viscosity and often cause problems such as partial degreasing in order to sufficiently exhibit the effect of improving drawability, and require extensive effort and time as a degreasing step.

Regarding the need for the degreasing step, conventional literature, for example, "Adhesive Technique Handbook" (Daily Industrial Newspaper, published July 1963, Digestion), 18 pages or less, and "Pluriethane resin" (Daily Industry) As reported on the newspaper's digestion (published in 1969, 44), page 115, page 239, it is common to require sweetening prior to adhesion but pretreatment for surface cleaning, and it is common sense among those skilled in the art that it is indispensable. The degreasing process penetrated the concept of an unavoidable process, became standardized, and had not been examined.

Generally, the surface of the metal which is a to-be-adhered body is covered with the oxide and hydroxide film, and may adsorb | suck various substances.

It is also commonly contaminated with grease for rust prevention and grease for cutting or rolling.

This grease is especially removed by solvents, detergents or alkalis because it has a large amount of adhesion and severely reduces the adhesive strength.

However, the oil partially adhered may spread through the entire surface of the solvent. In this case, the solvent to be washed was replaced with new ones and washed repeatedly.

When alkali or detergent was used, these remained on the surface of the adherend, which lowered the adhesive strength.

Accordingly, an object of the present invention is a process having a relatively large number of problems in the manufacturing process of a conventional polyurethane coating, in which a required portion of a core material formed by pressing a metal material is coated with a polyurethane, for example, a foam or a coating film, in particular, a degreasing step. In addition to solving the problem by eliminating the problem, it is possible not only to reduce the process and eliminate the problem, but also to secure the quality of the finished product as a product having the same or better performance as that of the conventional method. To provide.

In order to achieve the above object, the present inventors studied the adhesion state of the core material with the polyurethane foam or the polyurethane coating film in detail, and as a result, the chemical affinity with the polyol, especially isocyanic acid, of the isocyanic acid for forming the polyurethane By using a lubricant containing a compound containing a hydroxyl group, which is considered to be present, press-molding a metal material, sufficient adhesion between the core material and the elastomer is eliminated even if the degreasing step for removing the coating layer for lubrication of the core material, which is normally required, is omitted. It confirmed that it could ensure and came to achieve this invention.

Therefore, in the present invention, a core material formed by pressing a metal material coated with a lubricant containing a compound having a hydroxyl group is formed by reacting isocyanic acid with a polyol at a desired location of the core material, thereby covering the core material with polyurethane. The manufacturing method of the polyurethane coating body characterized by the above-mentioned.

Hereinafter, the method of the present invention will be described taking the instrument panel pad as an example.

The manufacturing process of this instrument panel pad is shown in a 1st table compared with the conventional method.

In the method of this invention, a core material is pressed and shape | molded by the metal material which apply | coated the lubricant containing the compound with a hydroxyl group first, but the said lubricant used at that time contains a replacement lubricant and a pulley oil.

A good example of a solid lubricant is H.A. There is a polymer lubricant (trade name Mill Bond) developed by MONTGOMERY, whose composition is indicated in Patent Publication No. 51 (1976) -3702.

As another preferred example, so-called polyol oils containing various third substances, for example, polyfunctional alcohols, may be added to the solid lubricant.

There are many kinds of polyol oils next, for example, EX-1695B (manufactured by Asahi Den Chemical Industries, Ltd., trade name).

Specifically, for example, a steel plate coated with a lubricating agent and a solid lubricant that serves as a lubricating lubricating agent after the manufacturing step of the steel plate is commercially available.

However, when only antirust oil is applied to a metal material, it presses after apply | coating the lubricant used for the said invention before press work.

The core material press-molded as described above is placed in a mold, placed in a predetermined position in the mold, and then injected with a component for forming a polyurethane foam, and then reacted for a predetermined time. Also, the foamed structure in which the core is covered with polyurethane is taken out of the mold or the polyurethane coating is applied to the core. In the case of the instrument panel pad, the core material has no rigidity only in the skin and the foamed urethane, and since the attachment of the instrument panel pad is difficult, the steel sheet is placed as the core material as described above.

In general, the skin is formed by vacuum molding a semi-hard ABS sheet mixed with vinyl chloride or by using a slush molded product of vinyl chloride, but is formed by coating a vinyl chloride side. It is also possible to use one skin (integral skin) or one made of foamed polyurethane itself.

Next, in the present invention, the polyuratane foam is made by reacting a polyol, isocyanic acid and a blowing agent suitably selected. In order to foam the two liquids in a mold, there are the following methods.

1) Injection foam to infuse by foaming without applying pressure: Hot curing (bot cure) that applies heat at the time of foaming by selected raw materials or cold cure (foaming) at room temperature.

2) Rapidly foaming by applying pressure, ie RIM (Reaction Injection Molding).

This method is not currently used in the manufacture of instrument panel pads.

According to the method of the present invention as described above, the degreasing step required by the conventional method by using a core material press-molded by applying a lubricant containing a compound containing OH when coating the surface of the core of the core material with polyurethane and The accompanying process can be omitted, and furthermore, the adhesion between the core material and the polyurethane is good, which makes it possible to produce an elastomer having the same or higher quality than the conventional method.

In this case, the bonding mechanism between the core and the polyurethane is considered as follows. Although the theory of adhesion has been described in various documents, it is not possible in all cases to provide sufficient adhesion even if the degreasing step is omitted.

As for the adhesiveness between the polyurethane material and the metal in the present invention, it is known that among the polyol oil and the isocyanic acid, the isocyanic acid is contacted with metal, silicate, rubber, etc. by itself. It is known that a chemical first bond is produced by directly combining with a hydroxide by hydrolysis of an oxide film of ethylene.

In addition, isocyanic acid reacts with the water that is electrically adsorbed on the metal surface, and as a result, it is thought that the adhesive force due to the electric adsorption is also generated.

Since the press lubricating oil used in the present invention contains a compound having a hydroxyl group as described above and reacts with or is affinity with a polyurethane beverage, even if a lubricant layer is present on the metal surface, this results in the Not only is the bond not to be hindered, but the lubricant itself is also considered to maintain the adhesion between the polyurethane and the metal surface by forming an isocyanic acid and a urethane bond.

On the other hand, in the case of applying a mineral oil press lubricating oil by the conventional method, the mineral oil does not react with isocyanic acid and has a very small number of terminal reactive groups (carboxyl groups, hydroxyl groups) or no terminal reactive groups. In addition, in the formation of a so-called urethane bond between water and cyanate which is electrically sucked on the metal surface, the lubricating oil prevents the isocyanic acid from being eradicated on the metal surface, and thus the bond between the urecil and the metal cannot be sufficiently obtained.

In addition, since press lubricants are generally high in viscosity and thickly applied, the difficulty of mixing isocyanic acid or polyol with lubricants further hinders the bonding of urecil and metal.

Therefore, it is thought that the degreasing process was essential.

TABLE 1

The invention is illustrated by the following examples, reference examples and test examples. In the examples, "parts" and "%" shall indicate "parts by weight" and "% by weight" unless otherwise specified.

Example 1

This embodiment is an example of manufacturing the instrument panel pad 1 displaying the cross-sectional shape shown in FIG.

The instrument panel pad 1 is fixed to the upper surface of the instrument panel 3 of the vehicle by the bolt 4 and the nut 5, and serves as a buffer against the collision of the human body.

6 is a glove box and 7 is its lid.

Moreover, the urethane foam 9 is filled in the structure between the core material 2 and the skin material 8 which were press-molded.

In manufacturing the instrument panel pad 1, first, 20 parts of commercial acrylic acid and 3 parts of styrene / maleic anhydride copolymer, 0.5 part of calcium stearate, and stearic acid are composed of 80% of acrylic acid and 20% of methacrylic acid. Solid solid lubricant coated with 3 to 5 (average 4 g) per 1 m square of steel sheet, commercially available Millbond MC-560 (Nippon Yushi Chemical Co., Ltd.) The treated steel sheet was punched and pressed to form a core 2.

At this time, for partial shapes such as deep draws, the equivalent or more stepping pressure was obtained as compared with the case of using commercially available press working oil (for example, high viscosity mineral oil-based lubricant commonly used). Subsequently, as shown in FIG. 2, the bottom of the set of molds 10 is placed at (11) (which is a mixed material of vinyl chloride and acrylonitrile butadiene styrene copolymer resin) and the skin agent 8 is used. ) Is sucked into the magnets 13 and 13 'fixed at a predetermined position in the upper frame 12 without undergoing a degreasing step, so that the space between the skin material 8 and the core material 2 is formed in the following second table. The component which forms the polyurethane foam 9 shown was injected, and it reacted under the manufacturing conditions shown in the following 3rd table, and obtained the instrument panel pad which has a skin.

TABLE 2

TABLE 3

Example 2

90 parts of laad oil as a coating layer of the second layer recommended by the maker of the mill bond after punching on a steel plate coated with 3 to 5 g of a solid lubricant and mill bond MC560 per square meter of steel sheet. An activator for a solid lubricant of 10 parts of butyl cellosorb was applied with a roller and scraped off with a doctorblade so that an application amount of 0.5 g or less per square m of the mill-bonded steel sheet was applied.

This double layer was pressed on a steel plate coated with a ring-shaped ring layer recommended by the mill bonder, and exhibited good deep drawability in which the core material 2 was molded. Subsequently, the degreasing step required in the same manner as in the first embodiment was omitted, and the skin material 8 was placed in the set of molds 10, and the polyurethane foam layer 9 was carried out around the core material 2. It formed in the same way and obtained the instrument panel pad 1 shown in FIG.

Example 3

As described in Example 1, EX-1695B (manufactured by Asahi Denga Kogyo Co., Ltd., trade name) as a polyol-based oil agent was 0.5 per square meter of steel sheet as a polyol-based oil agent. After apply | coating with a roller so that it may become g, it pressed and shaped the core material 2. As shown in FIG.

The obtained core material 2 was fixed in the metal mold | die 10 without degreasing like 1 in the chamber, the polyurethane foam layer 9 was formed in the periphery, and the instrument panel pad 1 was obtained.

Example 4

Solid paraffin containing 55% of solid paraffin, 20% of di long-chain alkyl ketones as a main component, 5% of fatty acid, 5% of glycerin fatty acid monoester, and 15% of 7% of ethylene oxide added to alkyl panol As a solid lubricant composition mainly consisting of, after punching a commercially available solid lubricant coated steel sheet obtained by applying a mixture of solid lubricants described in JP 53 (1978) -60340 to a thickness of 0.2 micron, Pressed.

Using the obtained core material (2) and fixing to the mold (10) without performing any degreasing step of the same method as the manufacturer of the solid lubricant coated steel sheet, the core material (2) and polyurethane foaming as in the first embodiment An instrument panel pad 1 with a vinyl chloride-based label 8 in layer 9 was formed.

Example 5

In order to achieve the purpose of press lubrication on an ordinary steel sheet (paraffin type anticorrosive agent was applied very thinly), polyol oil mainly made of polyol (EX-1695B, manufactured by Asahi Denga Kogyo Co., Ltd., brand name) And 4 g of viol per square meter of steel sheet. The steel sheet was punched out, pressed to form the core material 2, and then the instrument panel pad 1 was formed as in Example 1 without performing a degreasing step.

Example 6

Ethylene glycolol coating was applied after coating the lubricant-coated steel sheet obtained by coating a coating liquid obtained by adding 5% of a polyol to a solid lubricant as described in Example 1 on a steel sheet and coating 3 to 5 g of a solid lubricant per square meter. The liquid was used at a ratio of 2 g / m 2 to form a resin activated coating film, and then pressed to shape the core material 2.

The instrument panel pad 1 was molded in the same manner as in Example 1 without performing any degreasing treatment on the obtained core material 2.

Example 7

The core material 2 of the required shape was obtained by press molding the steel sheet treated with the solid lubricant coating as in Example 1 without applying ordinary high-viscosity mineral oil-based press working oil.

Subsequently, without performing the degreasing treatment on the solid lubricant coated steel sheet subjected to this molding, after completing coating with the paint described later, the polyurethane foam 9 is formed in the mold 10 and the instrument panel pad ( 1) was obtained.

Moreover, the objective of the completion of the coating by the said coating is to ensure aesthetics with respect to the component of the shape which is not partially covered by a foam mainly. As for the paint, in this example, in particular, 130 parts of two-component polyurethane coating desmoles N (manufactured by German Huerben Hubriquen Vier, trade name) (75%) did not require heating. A bond of 100 parts was selected for 800 (manufactured by German Bayer Co., Ltd.) and used as an equivalent value.

Inorganic pigments or dyes are used as the colorant, but for this example, the kind of the colorant has little direct relationship with the production method of the present invention.

Reference Example 1

Nippongo of high viscosity mineral oil press lubricating oil (for example, (paraffin series)) which is generally used after punching on steel plate coated with anti-last P2100 (manufactured by Nippon Seki Oil Co., Ltd. A minimum required amount was applied to Osusa Kuyusa # 660 and the like to form a core 2.

The obtained core material 2 is placed in a set of molds 10 without degreasing, which is normally required, and is formed of a mixture of vinyl chloride-ABS resin and formed between the TSms skin material 8 as in Example 1 The polyurethane foam 9 was formed, and the instrument panel pad 1 was obtained.

Reference Example 2

The steel plate coated with the solid lubricant of Example 1 was pressed to shape the core 2, and then degreased under the following conditions in a spray degreasing process.

Degreasing condition: Nippon Paint Lidrin # 16 1.5%, pH 10.2, bath temperature 55 ° ~ 65 ℃

Spray pressure 2kg / cm ² , time 2 minutes

Subsequently, after removing the degreasing liquid sufficiently, it was confirmed that the water wettability of the metal surface was visually confirmed by the presence or absence of water splashes, and then dried to obtain a sufficiently clean metal surface.

The following operation was carried out just like Example 1, and the instrument panel pad 1 was obtained.

Reference Example 3

The same steel sheet coated with the solid lubricant as in Example 1 was handled in the same manner as the core 2 in Example 7 until the press.

Prior to coating completion on the obtained parts, degreasing treatment was performed under the same degreasing conditions as in Reference Example 2.

After the degreasing liquid was sufficiently washed with water and confirmed that the surface of the steel sheet was clean, the two-component polyurethane coating material shown in Example 7 was coated.

This core material 2 was put in the metal mold | die 10, and the polyurethane foam 9 was formed around it.

[Test Example]

For the instrument panel pads obtained in Examples 1 to 7 and Reference Examples 1 to 3, to compare the cutting conditions between the polyurethane foam 9 and the core 2 and the deposition conditions of the coating films of Examples 7 and 3 Next, the test shown in Table 4 is carried out, and the obtained results are written together in Table 4.

TABLE 4

In the case of Examples 1 and 7, in the case of the steel sheet coated with a solid lubricant mainly composed of acrylic acid, acrylic acid was used as a coloring agent of paint, and the terminal carboxyl group (COOH) is hydrogen with metal. In addition to contributing to the formation of bonds, it also contributes to the formation of crosslinks by chemical reaction with isocyanic acid groups (OCN), so that acrylic acid acts effectively as a kind of cutting agent between the resulting polyurethane layer and the metal layer. It is thought that strength can be exhibited.

In addition, acrylic acid easily dissolves, penetrates, and diffuses with polyols, and in part, acrylic acid is trapped in polyurethane using a polyol as a medium, and the adhesive strength is secured by direct adhesion between polyurethane and metal. I think enough.

In addition, it is estimated that the force contributes complementarily between various molecules.

In Examples 2 and 6, larad oil or ethylene glycol is coated on the solid lubricant of Example 1, but -COOH group is contained in lad oil, and -OH group is contained in ethylene glycol. Of course, since the isocyanic acid and the urethane bond, after urethane foaming, the urethane foam forms a part of the urethane. Laad oil or ethylene glycol has little effect on the adhesion.

In Example 3, polyol oil is applied to the surface of the metal, but the polyol oil naturally contains a polyol which reacts with isocyanic acid to form a urethane bond. It does not inhibit the adhesion with.

In Example 4, all of the additives excluding the solid paraffin, i.e., long-chain alkyl ketones, fatty acids, glycerin fatty acid monoesters, and alkylphenols all have a CO group or an OH group reacting with isocyanic acid. Configure.

Therefore, the part of the additive component of the solid lubricating layer in contact with the metal surface is filled with urethane, and the metal and the urethane are directly bonded.

When the solid lubricant is applied thinly, paraffin is melted and melted in the urethane by the heat during urethane bonding, thereby increasing the area of the urethane in contact with the metal surface, thereby increasing the adhesive strength.

In Example 5, although a thin paraffin type rust preventive agent was apply | coated to the steel plate, it melt | dissolved by the heat at the time of making a urethane bond as mentioned above, and it thinks that it was mixed in urethane, and it is thought that it is not influenced by adhesive force.

In addition, the parts obtained in Reference Example 1 were subjected to the same test as in Example 1 in Table 4, and as a result, their performance was poor in numerical values, and metals and polyurethane were easily peeled off by contact with human nails. In the case where the same lubricant as in Reference Example 1 was used, it was found that it was difficult to omit the degreasing treatment.

In addition, it was found that the adhesive strength can be secured to the same level as in Example 2 after using a alkaline degreasing solution under the following degreasing conditions, heating sufficiently to remove the high-viscosity press oil coating and washing with water.

Degreasing condition: Nippon Paint # Lidrin 53S

Spray pressure 1kg

Temperature 55-65 degreeC, 65-70 degreeC

In addition, as shown in Table 4, the component obtained in Reference Example 2 obtained a checker test result for the adhesion of the coating film after the completion of the curing of the component in Reference Example 3, in which the adhesiveness was obtained. As shown in Fig. 7, none were found to be practically problematic.

However, the degreasing process involves many problems such as degreasing equipment, auxiliary equipment, degreasing agent, management of degreasing bath temperature, pressurized spraying or dipping, rinse cleaning treatment, and treatment of washing waste water. The manufacturing method which skipped degreasing is excellent.

The present invention has been described above with reference to an example of an instrument panel pad in which a metal core is coated with polyurethane, but such a member is separately used for applications such as armrests, crush pads, sun visor plates, annular handles, etc. as automotive parts. As shown, the present invention is also prepared for the so-called polyurethane integral skind form, which has a wide melting surface and forms an inner core by foaming with a foamed resin solution. The method is applicable and extremely useful industrially.

Claims (1)

After pressing a metal material coated with a lubricant containing a compound containing a hydroxyl group to form a core material, the poly-coated material is coated with a polyurethane by reacting isocyanic acid with a polyol in the required portion of the core material as it is. Method of producing urethane coating body.

Images